** Note: In order to encrypt external storage devices you will need to reformat your device. This will delete any data on your device so make a backup copy first! After it’s encrypted it will only be usable on a Macintosh computer.


  1. Plug your device into your Macintosh.
  2. Open the application Disk Utility from the Utilities folder.

  3. In the Disk Utility application, choose your device from the left pane.
  4. Click the “Erase” option at the top of the Disk Utility window.
  5. Give the disk your desired name, and from the Format pull down list, choose “OS X Extended (Journaled, Encrypted) as your format option.
  6. You will be prompted to set a password in order use this disk. Click “Choose”.
  7. Click the “Erase” button and wait for the disk to be formatted.

  8. When plugging the disk into this or another Macintosh, it will be necessary to enter the password set above.
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Last updated: 
May 19, 2016